L13 - Cardiovascualr System Flashcards
Give 2 examples of animals that use positive pressure tidal flow ventilation systems
1) Insect tracheal systems
2) Amphibian Buccopharyngeal pump
Give 2 examples of animals that use negative pressure tidal flow ventilation systems
1) Reptiles
2) Mammals
Give an example of a group of animals that use a unidirectional flow tidal ventilation system
Bird/reptile lungs - blood flows at right angles to the blood which is more efficient than pooling
What is the purpose of Bulk Transport
It bypasses diffusion as it takes the substance that the gas has diffused into away, allowing fresh substance to pick up more gas, maintaining a concentration gradient
Describe the general way open circulation systems work
In OSs extracellular fluid is squeezes through intracellular spaces as the animal moves.
A muscular pump usually assists the distribution of fluid in these areas, is simply propels the extracellular fluid through vessels to slowly trickle through the tissues and eventually return to the heart/.
Give a 2 examples of groups of animals that use open circulatory systems
Arthropods such as insects, and molluscs such as clams use open circulatory systems. The blood is pumped by a tubular heart and directed to different regions of the body through vessels that open into intracellular spaces.
What 2 disadvantages of an open circulatory system?
It is hard to direct fluid to specific part of the body if it is needed quickly
If 1 part of the system gets blocked the whole thing is blocked
Describe the general way closed circulatory systems work?
A system of vessels circulates blood separate from the interstitial fluid. Blood is pumped by 2 or more muscular hearts through a vascular system.
Some components of blood never leave the vessels
What kind of animals use a closed system
Vertebrates
Annelids
Some invertebrate groups
Give 3 advantages of a closed circulatory system
1) Speed - fluid can flow more rapidly through intracellular spaces, therefore transport gases, nutrients, and clear waste products is more rapid
2) Direction - by changing resistance in the vessels, closes systems can be selective in directing blood to specific tissues
3) Specialised cells - and large molecules that aid in the transport of hormones and nutrients can be kept within the vessels and can drop their cargo where it is needed
How can insects be so metabolically active but still use an open circulatory system?
Because they don’t rely on blood for gas exchange, they use the tracheal system
What are the systemic and pulmonary circulation’s?
Systemic: to and from the body
Pulmonary: to and from the lungs
What flow rates and pressures do the systemic and pulmonary circulations have individually?
Systemic: high flow rates, high pressure
Pulmonary: high flow rates, but HAS to be low pressures
What 2 ways can you change flow rate in blood vessels?
Pressure
Resistance - most common - vasodilation or vasoconstriction
What are the 4 chambers of a fish heart?
1) Sinus venosus - thin walled venous chamber
2) Atrium - large thin walled, initial site of blood acceleration
3) Ventricle - most muscular and main propulsive force for cardiac flow, chambers are separated by valves
4) Conus arteriosus - short in bony fish and amphibians, and not found in adult amniotes. Its a capacitance vessel and smooth’s out flow of blood to the gills
